Greek police fired tear gas to disperse crowds gathered outside parliament on Thursday to protest against a deal over the name of neighbouring Former Yugoslav Republic of Macedonia, as an at times angry parliamentary debate spilled into a third day.
Several thousand people massed outside the Greek legislature, some of them chanting "traitors" as lawmakers debated ratification of an agreement reached with the neighbouring ex-Yugoslav state last year.
Protesters are planning new rallies for Friday, before the vote takes place around 11:30pm AEDT.
The Greek parliament delayed the expected approval of the U.N-brokered deal by a day due to an increased number of lawmakers who wanted to have a say over the deal.
The so-called Prespes Agreement between Athens and Skopje changes the tiny Balkan nation's name to Republic of North Macedonia, ending a 28-year old dispute between the two countries.
Although Prime Minister Alexis Tsipras appears to have secured the support of at least 151 deputies in the 300-seat house to get the deal approved, opinion polls have shown most Greeks oppose the term "Macedonia" being used in any agreement.
They fear it could lead to territorial claims over Greece's largest northern province of Macedonia and an appropriation of Greek cultural heritage.
"We feel betrayed," Zografos Stathakopoulos, a 47-year-old protester, said on Thursday. "Most Greeks don't want this deal, but politicians are betraying us."
Supporters of the Greek Communist Party (KKE) protest against an agreement to rename Greece's neighbour as the Republic of North Macedonia, in Athens Source: Getty Images
Members of the Greek Communist Party (KKE) unfurled banners on the walls of the ancient Acropolis to protest against the deal on Thursday.
Protesters chanted "Long live Macedonia, long live Greece!", referring to the Greek province of Macedonia. Police chased protesters on Syntagma Square, the same area of large, violent protests in Athens on Sunday.
There were also protests in the northern Greek city of Thessaloniki.
Parliamentary speaker Nikos Voutsis said close to 230 MPs had wanted to have their say. Most are given six minutes to speak, a rule which has been routinely broken in the highly-charged session, which opened on Wednesday.
The accord has already been ratified by Macedonia's parliament and Greek parliamentary endorsement is necessary for the country to eventually join the European Union and NATO.
'Right side of history'
In addition to normalising relations between the two countries, implementation of the agreement will open the door for Macedonia to join the European Union and NATO, hitherto blocked by Athens' veto.
But in Greece, the name of its neighbour continues to fuel controversy in politics and society, a few months ahead of parliamentary elections scheduled for October.
Last week, Tsipras's ruling coalition fell apart as a result of the controversy but he then narrowly won a confidence vote, setting the stage for the name-change vote in parliament.
His leftist Syriza party has 145 MPs and enough independent members have pledged their support to secure approval of the deal.
Speaking to AFP on Thursday, Macedonia's Foreign Minister Nikola Dimitrov said supporters of the deal were "on the right side of history".
He said the agreement offered a valuable model for resolving a number of complex disagreements in the Balkans.
Dimitrov, who was one of the top architects of the June deal along with Nikos Kotzias, his Greek counterpart at the time, said the compromise had created "a climate (in which) the impossible is actually possible".
'Concerns exaggerated'
On the right, New Democracy leader Kyriakos Mitsotakis said the agreement "creates new problems" and "awakens nationalism".
"Your foreign policy is superficial and ignorant... you should be ashamed," he told leftist lawmakers.
Conservative ex-PM Costas Karamanlis, who thwarted Macedonia's NATO entry a decade ago, said the deal talks were conducted "with unjustified haste".
For many Greeks, especially in the north where the province of Macedonia is the birthplace of Alexander, the name "Macedonia" belongs to Greek historical heritage.
But Tsipras insisted Thursday: "We never had a Macedonian language. Alexander the Great spoke Greek."
Some even fear their neighbour has territorial designs on its namesake Greek province.
"These concerns are exaggerated," Yannis Armakolas, professor of political science at the University of Thessaloniki, told AFP.
Protesters demonstrate next to the White tower against an agreement to rename Greece's neighbour as the Republic of North Macedonia, in Thessaloniki Source: Getty Images
He deplored what he called a lack of party consensus and "real public debate" on an issue of national importance.
"If the agreement does not come into effect, the consequences of the failure will be profound and both sides might well reconsider many elements that had been agreed to," UN mediator Matthew Nimetz said in an interview with Greek news agency ANA.
Nimetz said reaching a new agreement "would take years, not months, given that all the issues would once again be on the table, and given that there are likely to be different political dynamics in both countries, as well as changes in the regional and global environment."
With Reuters
